While the paint was drying, I go into a small scratch Shuttle Tydirium around a blue 2mm micro LED. I reduced 3-view blueprint for a length of 1.2 cm. The metal rods welded on the LED are embedded in the upper wing. They bring electricity from the connector hidden in the hangar bay.

The 2 escort Tie are only 4 mm long. The wings are plastic card, the rest is cross of brass rod welded and some white glue to the central ball.

And I had to go with the optical fibers step (a really boring step)
They are folded in two, the loop staying on the outside (except for the bridge... no reason there... just forget this trick when I started it...). They remain well in place, do not escape and fill two holes simultaneously.

They are then set with a mixture of white glue and black paint.

The fibers are then grouped to warm white or red LED, inserted into tubes (evergreen or recycling of body pens or felt pens).
The white / red allocation is made like the original for the bridge, but randomly elsewher as it was too complicated to do, and besides the right side of the studio model was less detailed and included only very very few fibers (that was the left side that was filmed and then the image reversed).

The tubes LEDs are painted in white to enhance light diffusion inside.

The 3 main thrusters are warm white LED, they are entrenched in truck covers (clear resin parts provided in the kit), painted black then aluminium.

The 4 secondary thrusters are cool white LED (they indeed have a bluish tint on the studio model). They are glued to bottom of tubes, themselves fit into the tubes glued on the engine bells, which will be fixed later.

On the set of model, some bulbs were exposed in the trenches, and lit comprehensive areas in the trenches. To avoid over-lighting the trenches, I use light rods (the bulb being so remote and hidden inside the model).
These light rods are made from frosted clear rods, tubes and warm white LED.
These 11 rods are then glued to the back of the trenches.
(unfortunately, no photo of the installation step)

As I am not sure of me with these light rods, so I placed a switch on the sub-circuit, hidden in the details of a side trench.
A second switch is placed on the sub-circuit of the engines, in case they would interfere during photo shots.

The underside support goes through the location of belly dome. The dome kit part was not glued, as I kept it to hide the hole when I will use the lateral support.
As the dome is an important visual element below the Stardestroyer, that bothered me to not have it. So I made a mold of the kit part, to have a copy which I hollowed out the center.

To fix these domes, I use two different methods :

the complete original dome is held with a water cistern blocking unit from a (new) toilet kit. It is glued to the dome.

For the hollowed dome, I first imagine a system of brackets but finally went with magnets : magnets in the dome, and screws in the stardestroyer belly.